From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 521DECA6017 for ; Sat, 10 Oct 2026 13:23:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jSn1IK04TkZcZee9zhz9sEIPssSjp24H+zQ/sP34SBE=; b=VeRjRcUwz1mJT0RBA/gQnwKnYh nElnzthyKD4mQTwmnDJmIkelnvttKGIYkNG8EuXlGFVRxqIQ3h66ve8Nt3IaCk4OLg9BI6fusxaDG ZtpKQGicN0fNZu1vu44wCqXHGcBzQnbtAuk9bsOoGOVXaGgwuQzqOfn7CTunTm7XKPGcCVz31BPqo MaBWF5dWj9iYXGup2A469UBDJCTG4vLJ5ULvGUePPXimXT+1u6zEghrbg3xqoEeDlWFCY7ctlJ7e4 GBFHn8rTCShQDaeUr4IIwwzKFV0+xwrQpxINDz0OCJDJofUJVjPPSH9YKQ4AgmevjXumiUdChk919 /XJ5vDVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xFX35-000000086R7-0rYD; Sat, 10 Oct 2026 13:23:40 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xFX33-000000086Qn-3r89; Sat, 10 Oct 2026 13:23:37 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 39128402B6; Sat, 10 Oct 2026 13:23:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6622A1F000FF; Sat, 10 Oct 2026 13:23:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791638617; bh=jSn1IK04TkZcZee9zhz9sEIPssSjp24H+zQ/sP34SBE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=P0fW5fFjAF5qEShD2FDUvhRLrpwuYauXz7mH0/BSGcs1DeAv1GtmOVVG/2URH7Nil Wp7IYW+Wv03cB9LfWZcRjNFYz0kCgtVvJncN3ac2E9G0ZIkIOdvjPHjh3vg52WlgNo 5Wlw/ejL90a14q4Vviu2IAatKuQrY5GO0AR9xa2hVWWg5/UwMnYgO3AgB+jB+lW+Vc CzV6C9D/37DcbFx8Guens1jLZhndt+gROqpJ0cPyfu1x5sKaz92g9XWah1cqwpx6Wx F5ZvDMs8i/Le+rGQB1xi9V8X65teOuzLFUWnMdc/8rWz+9kJ58E5S9pgQZHGzWWwFC EZyVOU+A0eHzg== Message-ID: <5d20f9b8-9085-49df-87df-05f29f1496a1@kernel.org> Date: Sat, 10 Oct 2026 14:27:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] riscv/mm: fix hotplug page-table destructor handling To: Muchun Song Cc: Muchun Song , akpm@linux-foundation.org, linux-mm@kvack.org, stable@vger.kernel.org, osalvador@suse.de, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, linux-riscv@lists.infradead.org, agordeev@linux.ibm.com, kevin.brodsky@arm.com, bjorn@rivosinc.com, apopple@nvidia.com, linux-kernel@vger.kernel.org References: <20261008073021.2512665-1-songmuchun@bytedance.com> <20261008073021.2512665-3-songmuchun@bytedance.com> <664510b2-3510-499f-aab5-ceddfcc82581@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 10/10/26 04:58, Muchun Song wrote: > > >> On Oct 10, 2026, at 04:37, David Hildenbrand (Arm) wrote: >> >> On 10/8/26 09:30, Muchun Song wrote: >>> RISC-V uses the same memory-hotplug teardown code for the linear map and >>> vmemmap, although their page-table pages are not always allocated in the >>> same way. Late linear-map allocations run page-table constructors, while >>> vmemmap and early allocations may provide constructor-free pages. >>> >>> The PTE path unconditionally runs the destructor, which is wrong for >>> constructor-free vmemmap tables. The PMD path avoids that problem by >>> using is_vmemmap as a proxy for constructor state, but that assumption >>> will no longer hold once runtime vmemmap allocations use the normal >>> pgalloc helpers. >>> >>> Page-table constructors record their state in PG_table. Centralize >>> page-table freeing and use PageTable() to decide whether the destructor >>> is required. Keep reserved and constructor-free pages on their existing >>> freeing paths. >>> >>> Fixes: c75a74f4ba19 ("riscv: mm: Add memory hotplugging support") >>> Cc: stable@vger.kernel.org >>> Assisted-by: LLM >>> Signed-off-by: Muchun Song >>> --- >>> arch/riscv/mm/init.c | 29 ++++++++++++++--------------- >>> 1 file changed, 14 insertions(+), 15 deletions(-) >>> >>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >>> index 857f9a55039c..429a0b015ec1 100644 >>> --- a/arch/riscv/mm/init.c >>> +++ b/arch/riscv/mm/init.c >>> @@ -1486,10 +1486,19 @@ struct execmem_info __init *execmem_arch_setup(void) >>> #endif /* CONFIG_EXECMEM */ >>> >>> #ifdef CONFIG_MEMORY_HOTPLUG >>> +static void __meminit free_pagetable(struct page *page) >>> +{ >>> + if (PageReserved(page)) >>> + free_reserved_page(page); >>> + else if (PageTable(page)) >>> + pagetable_dtor_free(page_ptdesc(page)); >>> + else >>> + pagetable_free(page_ptdesc(page)); >> >> Similar thought, can't we detect that in pagetable_free() somehow and avoid >> requiring callers to handle that? > > I think we can, then pagetable_dtor_free() can be removed because pagetable_free > can handle the case of pagetable_dtor_free. That sounds much cleaner :) -- Cheers, David